Prepare the tomatoes: Start by blanching your tomatoes to remove the skins. Cut a small "x" on the bottom of each tomato and immerse them in boiling water for about a minute until the skins begin to peel away. Transfer them to an ice bath to cool.
Crush the tomatoes: Once cooled, peel off the skins, remove the seeds, and crush the tomatoes by hand or with a food mill.
Cook the garlic: In a large pot, heat the olive oil over medium heat. Add the minced garlic and sauté until fragrant, about 1 minute.
Add tomatoes. Stir in the crushed tomatoes and tomato paste. Mix until the paste is evenly distributed.
Add seasonings. Add the basil, oregano, salt, pepper, sugar (if using), and bay leaves. Bring the mixture to a simmer.
Simmer. Reduce the heat to low and let the sauce simmer uncovered for 2 to 3 hours, stirring occasionally, until it reaches the desired consistency for pizza sauce.
Prepare for Canning: While the sauce simmers, heat your mason jars. Sterilize lids and bands by boiling them in water for at least 10 minutes.
Add lemon juice. When the sauce is ready, remove the bay leaves and stir in the lemon juice.